Curved graphene nanoribbons: structure and dynamics of carbon nanobelts

Abstract

Carbon nanoribbons (CNRs) are graphene (planar) structures with a large aspect ratio.Carbon nanobelts (CNBs) are small graphene nanoribbons rolled up into spiral-likestructures, i.e. carbon nanoscrolls (CNSs) with a large aspect ratio. In this work weinvestigated the energetics and dynamical aspects of CNBs formed from rollingup CNRs. We have carried out molecular dynamics simulations using reactiveempirical bond-order potentials. Our results show that, similarly to CNSs, CNBformation is dominated by two major energy contributions, the increase in the elasticenergy due to the bending of the initial planar configuration (decreasing structuralstability) and the energetic gain due to van der Waals interactions of the overlappingsurface of the rolled layers (increasing structural stability). Beyond a criticaldiameter value these scrolled structures can be even more stable (in terms of energy)than their equivalent planar configurations. In contrast to CNSs that requireenergy-assisted processes (sonication, chemical reactions, etc) to be formed, CNBs can bespontaneously formed from low temperature driven processes. Long CNBs (length of∼30.0 nm) tend to exhibit self-folded racket-like conformations with formation dynamics verysimilar to the one observed for long carbon nanotubes. Shorter CNBs will be more likely toform perfect scrolled structures. Possible synthetic routes to fabricate CNBs from graphenemembranes are also addressed.